In 1847, a surveyor named Arthur Penhaligon walked the docks of Liverpool with a ledger that would have looked remarkably familiar to a modern general contractor. He was tasked with pricing the timber for a series of new warehouses. Penhaligon, obsessed with the immediate bottom line of the merchant guilds, recorded the cost of Baltic pine versus English oak strictly by the cubic foot.

He was praised for his efficiency, but three decades later, his ledgers were used in a court of law as evidence of professional negligence. The pine had rotted in the salt air; the warehouses were leaning like tired old men. Arthur had captured the price of the wood at the moment of the sale, but he had failed to account for the price of the air that would eventually eat it.

Fast forward to a Thursday afternoon in Denver. Gina, the owner of a thriving design-build firm, is staring at a spreadsheet. The room is quiet, save for the hum of an HVAC system fighting the mile-high heat. Gina is doing what every project manager in the country does: she is sorting a column in her estimating software from “Low to High.” The column is labeled “Installed Cost Per Square Foot.”

The Mathematical Masterpiece That Tells a Lie

The software is elegant. It accounts for material costs, waste factors-usually around 11% for this particular profile-labor hours, markup, and local taxes. It is a mathematical masterpiece that tells a total lie. It tells the homeowner that the cheapest option today is the cheapest option.

But as Gina’s eyes scan the rows, she realizes there is no column for the year 2029. There is no row that accounts for the scaffolding rental that will be required in seven years when the “natural” finish begins to peel and grey under the intense UV radiation of the Colorado sun.

If you only measure the cost of the board today, you sincerely believe you are being a good steward of your client’s budget. You feel responsible, even virtuous, for finding the $6-per-square-foot option over the $14-per-square-foot one. But you are effectively handing the client a bill that arrives in the mail very slowly, one weekend at a time, delivered by a man with a sander and a can of stain.

As an archaeological illustrator, my job is to look at what remains after the humans have left. I spend my days drawing the “ghosts” of structures-the stains in the soil where a post once stood, or the specific way a pigment has bonded to a ceramic shard. I’ve noticed that the most “expensive” buildings in history were often the ones built by people who didn’t use spreadsheets.

They used a different unit: the generation. When you look at the decay patterns of 19th-century cladding, you can see exactly where the builder prioritized the immediate cost over the longevity of the joint.

From Static Nouns to Dynamic Verbs

This brings us to the technical reality of how estimating actually works in the modern remodeling industry. Most firms use a “take-off” process. We take the architectural drawings, calculate the total surface area, subtract the windows and doors, and apply a unit price. It’s a clean, clinical process.

But “Unit Price” is a static noun. Siding is a dynamic verb. It is a material that is constantly “doing” something-expanding in the heat, contracting in the cold, absorbing moisture, or shedding it.

If we were to be honest, the spreadsheet should have a “Maintenance Velocity” column. For example, if you choose a traditional cedar plank, the velocity is high. Within 36 to 48 months, the moisture-content fluctuations will begin to stress the cellular structure of the wood. The tannins will migrate. The finish will break down.

At that point, the cost per square foot isn’t $8 anymore; it’s $8 plus the cost of labor to strip the failed coating and re-apply a new one. This is where the shift toward Composite Siding becomes less about “premium materials” and more about accurate accounting.

When a homeowner looks at a shiplap profile in a finish like Peruvian Teak or Brazilian IPE, they are often comparing it to the price of the raw timber equivalent. The spreadsheet says the composite is more expensive. The spreadsheet is forgetting that the composite board is engineered with a wood polymer substrate that doesn’t care about the five threats: fading, moisture, rot, mold, and insects. It is a material that has been “frozen” in its best state.

I remember a project in the Pacific Northwest where the architect wanted a very specific “Arctic Oak” look for a contemporary facade. The client, a data scientist, spent three nights building his own spreadsheet. He didn’t just look at the price of the boards. He looked at the cost of the specialized labor required to maintain a natural oak facade in a rainforest environment.

He realized that after just twelve years, the “cheaper” wood option would have cost him 214% more than the high-impact composite. He wasn’t buying siding; he was buying a fixed cost.

The 7 Realities Your Spreadsheet Ignores

I once spent a week illustrating the foundation of a Roman villa in what is now southern France. The builders had used a specific type of volcanic ash in their concrete. It was undeniably more expensive to transport that ash across the Mediterranean than it was to use local lime.

But they did it because they were measuring in centuries. They knew that the “cost per square foot” of a collapsed roof is infinitely higher than the cost of a resilient one.

Beyond the Front-End Negotiation

Back in Denver, Gina finally closes her spreadsheet. She doesn’t change the numbers-the numbers are what they are-but she adds a new tab. She labels it “Total Cost of Ownership: Year 1 to Year 20.” She starts typing in the cost of the recurring maintenance for the cheaper materials. She adds the price of the ladders, the cans of Weathered Oak stain, and the lost Saturdays.

When she shows the new tab to her clients, the conversation changes. It’s no longer a negotiation about how to save a few thousand dollars on the front end. It’s a discussion about how to protect the next twenty years of their lives.

They look at the finishes-the Graphite Charcoal Gray, the American Walnut, the Cedar-and they realize that the beauty of these boards isn’t just in the grain. It’s in the fact that the grain will still look like that when their children are graduating from high school.

We have been conditioned to believe that “value” is the same thing as “low price.” But in the world of exterior cladding, a low price is often just a down payment on a lifetime of chores. If you are building for the long haul, you have to stop thinking like a buyer and start thinking like a surveyor. You have to account for the air, the sun, and the insects.

I’ve seen too many beautiful homes become burdens because the owners were responsible enough to pick the cheapest option on a spreadsheet that didn’t have enough columns. Don’t be Arthur Penhaligon. Don’t build a warehouse that will lean in thirty years because you saved a few pennies on the cubic foot today.

Choose the material that honors the time you haven’t lived yet. Choose the one that lets you stay off the ladder and in the yard, looking at a facade that hasn’t aged a day, even if the world around it has.